fix: scroll to bottom when setting a channel (#5748)

src/widgets/dialogs/EmotePopup.cpp

@@ -168,10 +168,11 @@ void addTwitchEmoteSets(const std::shared_ptr<const EmoteMap> &local,
 void loadEmojis(ChannelView &view, const std::vector<EmojiPtr> &emojiMap)
 {
     ChannelPtr emojiChannel(new Channel("", Channel::Type::None));
+    // set the channel first to make sure the scrollbar is at the top
+    view.setChannel(emojiChannel);
+
     emojiChannel->addMessage(makeEmojiMessage(emojiMap),
                              MessageContext::Original);
-
-    view.setChannel(emojiChannel);
 }
 
 void loadEmojis(Channel &channel, const std::vector<EmojiPtr> &emojiMap,

src/widgets/dialogs/ReplyThreadPopup.cpp

@@ -237,9 +237,6 @@ void ReplyThreadPopup::addMessagesFromThread()
             sourceChannel->getName(), Channel::Type::None);
     }
 
-    this->ui_.threadView->setChannel(this->virtualChannel_);
-    this->ui_.threadView->setSourceChannel(sourceChannel);
-
     auto rootOverrideFlags =
         std::optional<MessageFlags>(this->thread_->root()->flags);
     rootOverrideFlags->set(MessageFlag::DoNotLog);
@@ -258,6 +255,9 @@ void ReplyThreadPopup::addMessagesFromThread()
         }
     }
 
+    this->ui_.threadView->setChannel(this->virtualChannel_);
+    this->ui_.threadView->setSourceChannel(sourceChannel);
+
     this->messageConnection_ =
         std::make_unique<pajlada::Signals::ScopedConnection>(
             sourceChannel->messageAppended.connect(